Custom RAM Timings for GPU's with GDDR5 - DOWNLOAD LINKS - UPDATED

[Truthchanter]

Are there any publicly available custom memory strap timings for the rx 400 series? (samsung, elpida, or hynix)

Here's the Samsung strap I'm currently working on:
777000000000000022CC1C0010625C49D0571016B50BD50900400700140514207A8900A00300000 0191131399D2C3617

It's the 1750 strap with RRD=5, FAW&32AW=0.  It's stable at 2100 on my Sapphire Rx470.  The previous custom strap I tried was based on the 1625 strap, and I would start getting a lot of errors over 2000.  I just started working on it today, so there's more tweaking to do (like trying a lower tRC for RAS).

Nicely done
Lets see the final results.

Small adjustments to your timing based on my experience : 777000000000000022CC1C00CE615C45C0571016B30CD50900400700140514207A8900A00300000 0151031399D2C3617

Thanks! Nice improvement over the regular 1750 strap. Now the question is... will this 1750 samsung strap work with 480s with samsung (and then both 4gb and 8gb?)

If you have one of the first 4G samsung batches, it will work and even improve even more. (because you can unlock those to 8G)
If you have a newer batch of those 4G samsung's, it will most probably run but won't run stable.

Greetings

Why won't it be stable? Would this only be stable for reference cards?

Different chips, but both Samsung.

Is there a way to know if the chips are different? I'm looking in Polaris Bios Editor and I see my old samsung chips are K4G8 while new ones are K4G4.. device id seems the same with them 0x91

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[Eliovp]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

If it's a Strix you might have memory voltage control, have you tried/checked this?

[lexele]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

I may try your strap on a gygabyte rx 480, VRM stays very cool on that card. I'll let you now.

[lexele]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

I may try your strap on a gygabyte rx 480, VRM stays very cool on that card. I'll let you now.

I was able to run it at 2050 mem clock, compared to 1500strap I went from 29.4 to 29.7 but with more memory errors.

[Ambros]

Thank you so much for releasing those tool! They are amazing and allows us normal to deal with HEX.

Usually what can be the improvement from a shitty copied timing vs a carefully crafted rom? I'm talking about both power consume and hashrate

[nerdralph]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

If it's a Strix you might have memory voltage control, have you tried/checked this?

I believe their custom VRM chip does control the memory voltage, but I haven't looked into it much.  Since the RAM is not cooled (no thermal connection to the heatsink), I thought bumping the memory voltage would make things worse.  The tuned 1625 strap is working quite well so far.  It tested OK at 2000, and now I'm trying 2050.

Once I've found the limit, I may look into the memory voltage to control power use, and see if it is stable with lower memory voltages.

[lpedretti]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

If it's a Strix you might have memory voltage control, have you tried/checked this?

I believe their custom VRM chip does control the memory voltage, but I haven't looked into it much.  Since the RAM is not cooled (no thermal connection to the heatsink), I thought bumping the memory voltage would make things worse.  The tuned 1625 strap is working quite well so far.  It tested OK at 2000, and now I'm trying 2050.

Once I've found the limit, I may look into the memory voltage to control power use, and see if it is stable with lower memory voltages.

I have a Strix, pretty sure it doesn't work.

EDIT: Wait... wait... there's something here....

Be careful! It may bite!!

[Eliovp]

It's based on the 1625 strap, since the 1500 strap wasn't stable for me beyond 1875.

That's very strange, I have several rx with hynix and the 1500 strap is the most stable at least up to 2050.

Maybe your cards have better cooling for the RAM?  This is an Asus Strix.  After tuning the 1625 strap, it was stable at ~27.2Mh with a 1950 mem clock.  Now I'm testing 2000.

If it's a Strix you might have memory voltage control, have you tried/checked this?

I believe their custom VRM chip does control the memory voltage, but I haven't looked into it much.  Since the RAM is not cooled (no thermal connection to the heatsink), I thought bumping the memory voltage would make things worse.  The tuned 1625 strap is working quite well so far.  It tested OK at 2000, and now I'm trying 2050.

Once I've found the limit, I may look into the memory voltage to control power use, and see if it is stable with lower memory voltages.

I have a Strix, pretty sure it doesn't work.

EDIT: Wait... wait... there's something here....

Be careful! It may bite!!

It appears I can control memory voltage! Sweet!

Some can some can't

[nerdralph]

It appears I can control memory voltage! Sweet!

Did you have to directly control it via i2c, or was it easier than that?

[Eliovp]

It appears I can control memory voltage! Sweet!

Did you have to directly control it via i2c, or was it easier than that?

Yes and no. Used the VBIOS.

00 8D ** 00 VDDC control
00 8E ** 00 MVDDC Control

you can easily add it into the rom.

[Truthchanter]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

[laik2]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

The strap works on both versions, the only diff is it will be more stable on 4G version.

[Truthchanter]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

The strap works on both versions, the only diff is it will be more stable on 4G version.

Thanks, maybe I wasn't clear though. I understand it is supposed to work on both versions, my question is about newer gpus with "different samsung chips" like it seems my nitro has a different samsung chip but may still be compatible

[nerdralph]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

You can do the same mods; RRD=5, ACTRD=16, FAW&32AW=0.  If you can't understand the offsets, just use my mod tool:
https://github.com/nerdralph/strapread/blob/master/strapmod.py

[Truthchanter]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

You can do the same mods; RRD=5, ACTRD=16, FAW&32AW=0.  If you can't understand the offsets, just use my mod tool:
https://github.com/nerdralph/strapread/blob/master/strapmod.py

Thanks how do I run this in Windows? I'm assuming I just enter in like the default 1500 or 1750 strap and this mods it as an output text?

[kilo17]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

You can do the same mods; RRD=5, ACTRD=16, FAW&32AW=0.  If you can't understand the offsets, just use my mod tool:
https://github.com/nerdralph/strapread/blob/master/strapmod.py

Added link in the OP

[doktor83]

you could link the ohgod decoder and checksum fixer i compiled, so some windows guys could use it too.
I compiled the tool too but that isn't working too well on win without some rewriting

[nerdralph]

you could link the ohgod decoder and checksum fixer i compiled, so some windows guys could use it too.
I compiled the tool too but that isn't working too well on win without some rewriting

Most windoze users are masochists, so using software should come with some suffering. :-)

[nerdralph]

I'm still not sure how I can know which samsung mem chips I can use the custom strap timing posted recently in this thread for (or more specifically which samsung mem chips i CANNOT use the strap for).

It was said to be used for K4G4, and old 8gb ref cards.

I've looked in Polaris bios editor and noticed on 2 different cards of mine, both samsung mem, they both start with K4G4 but have different characters after those 4.

Another odd thing I tried before I read here was using the custom strap on my new sapphire 470 4gb nitro (samsung mem) and it seems to be working. Odd thing being the default 1750 strap for this nitro is different from the default 1750 of the older samsung chips that this strap seemed to be said to be designed for.

Overall, how can I tell which samsung mem chips may not be stable with this? (and same for the hynix one recommended here)

You can do the same mods; RRD=5, ACTRD=16, FAW&32AW=0.  If you can't understand the offsets, just use my mod tool:
https://github.com/nerdralph/strapread/blob/master/strapmod.py

Thanks how do I run this in Windows? I'm assuming I just enter in like the default 1500 or 1750 strap and this mods it as an output text?

It takes the strap to modify as an argument, and prints out the modified strap (along with info about the old and new values in the strap).

[nerdralph]

For the lazy fools out there, I whipped up a cgi version of my strap mod utility.

Code:

http://doreymills.ca/cgi-bin/strapmod?555000000000000022CC1C00AD515A3EC0570E142D4A64080048C700030114207A8900A003000000150E2A3186272E16